Do you think the potential buyers may be running your house down a little as an opening gambit for negotiating on price? If so: it's to be expected, I think.
Sadly, I think this is very common. A lot of buyers seem to act like insurance company loss-adjusters (or a certain company that buys any car, so I hear) in actively looking for anything they can to justify paying you less, even if there's nothing actually wrong. House gaslighting, maybe?!
We sold a house in 2003 and the buyers insisted on a drain survey (fine). They didn't find anything at all wrong with them, but expressed great concern that they weren't specified to 2003 standards, and expected a big price reduction to enable them to 'fix' this. The drains were put in to current standards, 20 years earlier, when the house was built, and hadn't caused us any problems whatsoever.
We did eventually sell to them and took a rather low offer as we really needed to sell ASAP and the local market wasn't great at that time. I would be utterly astounded if the original 1982 drains are not still in place to this day. Demanding a discount for spurious reasons is one thing, but then having to actually use the money you 'saved' on those unnecessary repairs when you could use it for any number of other things that will make a difference to your life is quite another.
I believe this is a common ploy used by car hire firms, who somehow instantly know to check, say, under the bumper where they 'find' a hidden cosmetic scratch and bill the customer (an inflated amount) to repair it. Of course, they don't ever repair it as firstly, they want the money as profit rather than wasting it on a pointless touch-up job and, secondly, if they did get it seen to, they wouldn't be able to charge every other customer for fixing the exact same 'problem' for years to come.
I also take issue with the whole 'modernising' suggestion. Naturally, there will be properties with very old wiring, a clapped-out boiler, extremely dated and faded decor etc - but I think it's often used as a PA way of objectively 'justifying' criticism (and subsequently a hefty price reduction) rather than just being honest and saying "There's nothing inherently wrong with this, but it's not to our taste, so we'd want to change it to something we like better and that would cost money. We would rather that you pay this money than we do".
There are also people who want the 'double bunce'. They'll see a house that's priced at £80K less than comparable houses and the fact that it needs a lot of work is clearly stated as the reason for the low price. They then go to view it, express horror at the work that needs to be done, claim that it will cost £100K to do it (much more like £50K realistically) and then demand the already-reduced-to-take-account-of-it-price be reduced again to take account of it. It's so obvious that they're blagging it as, if the house truly was such a horrific monstrosity to them, they wouldn't have looked twice at the advert, let alone be desperate to buy it (albeit at a massively reduced price). They're probably the same people who would buy a £20 latest-model iPhone on eBay, labelled clearly as 'Broken - spares or repair' and with pictures of big scratches and smashed screen - and then demand a refund and leave appalling negative feedback.
As the PP said with the 'too small' room whose dimensions had already been clearly advised, some people don't seem to have any ability to home in on their personal requirements and immediately disregard options that don't suit or appeal. They don't/won't accept that, just because it's not for them, that doesn't make it worthless to everybody. I like big, spacious cars with room for loads of luggage and general junk so I wouldn't view a 2-seater sports car, but that doesn't mean that I consider such cars categorically unwanted by everybody. For some, it may just be a power trip and they get off on viewing small flats and smugly informing the sellers that it isn't as desirable as a large house.
There are people on MN who do the same with threads - instead of ignoring something that doesn't interest/affect them and just scrolling by like normal people, they feel the need to click on the thread and 'inform' everybody just how stupid/pointless/boring/untrue they believe the subject to be. They don't seem to see the irony of actively choosing to spend their time to tell people who couldn't care less (and wouldn't know they were there anyway) that they deem it unworthy of their time.